Disneyland parks open 24 hours: Happiest All-Nighter on Earth?

Hundreds of people flocked Friday to Disneyland and Disney California Adventure Friday, which opened for 24 straight hours beginning at 6 a.m.

The Magic Kingdom Park in Orlando, Fla., was also opened for the "Monstrous Summer All-Nighter," part of the promotion for the entertainment giant's upcoming movie, "Monsters University."

The event marked the first time all-night opened for all three parks, Disney officials said.

The last 24-hour event at Disneyland -- on Leap Day 2012 -- caused several headaches after a large after-work crowd overwhelmed the park, prompting officials to close gates for several hours. Traffic was snarled for miles as the parking structure nearly reached capacity, and many visitors voiced frustrations on social media.

Disneyland spokeswoman Suzi Brown told KTLA extra precautions had been made for the 2013 event, such as bringing in extra police officers and requiring staff to park off-site. Annual pass holders were also asked to carpool, she said.

“We worked really well with the city of Anaheim this year and traffic control to help mitigate all those problems,” Brown told the television station. “We’re fully staffed in our parking lots just to ensure that guests get in and to the park as quickly as possible."

Many Disney enthusiasts took no chances. Scores of visitors camped outside the park gates as early as Thursday.

“You meet friends, you meet new people from all over the world and you get to create experiences you couldn’t ever do at any other place except Disney,” Victor Serrano told KTLA from the front of the line.